Nothing much I can do about that, as the navbar is a fixed element detached from the flow of the page, thus I'd have to write some JS to get the height of the navbar and then alter the heading top padding accordingly. But that solution would only be responsive if then reacted to the window resize event and recalculated..... so as Mary suggests, remove the amount of items on the menu bar so that it's one line.
Additional, removing 'pull-left' from 'nav-collapse collapse' seems to help a bit but not by much. And the padding on '.navbar .nav>li>a' could be reduced.
Something for another day.